Very little has been done in the area of reed switches using a non-magnetic reed with a magnetic reed. Ellwood U.S. Pat. No. 2,264,746, Karrer U.S. Pat. No. 2,922,856, and Bentz U.S. Pat. No. 3,359,385 do disclose magnetic reeds working in conjunction with non-magnetic reeds; however, in each instance, there is a third reed which is magnetic and the actual operation of the switches is dependent upon a magnetic field acting upon the two magnetic reeds to cause them to close together to complete an electrical circuit at the same time as the two magnetic reeds complete a magnetic circuit. In these patents, the magnetic forces bring the reeds together so that the magnetic circuit is closed. The operation of the switches of this invention are not at all based upon the completion of a magnetic circuit as is typical in prior art magnetic reeds. Operation of this invention is dependent only on the attraction or repulsion of a single reed and the magnetic forces as they affect this reed. There is no completion of a magnetic circuit when the device is operating as in the case of the prior art, where the non-magnetic reed is merely positioned for a single pole-double throw system in which one of the magnetic reeds rests against the non-magnetic reed prior to operation of the magnetic field effect.
In addition to the art referred to, attention is called to DeFalco U.S. Pat. No. 3,283,274 and Shlesinger U.S. Pat. No. 3,760,312 which are typical of the prior art not including a non-magnetic reed.
Attention is also called to our U.S. Pat. No. 3,893,051 of July 1, 1975, which discloses electromagnetic devices operating on a typical reed system such as disclosed in this invention.
Historically, latching, i.e., a system in which a reed is carried to one side or the other and maintains its latched or unlatched position as the case may be, even after the magnetic field is either turned off or removed as, for example, by removing the magnet, has required extremely complex and expensive equipment. There has been no simple reed structure available which is both compact and inexpensive. In some instances, latching had to be carried on by a whole series of switches rather than a single unit.